Evaluating Titan2d Mass-Flow Model Using the 1963 Little Tahoma Peak Avalanches, Mount Rainier, Washington
Journal of Volcanology and Geothermal Research 139 (2005) 89–102 www.elsevier.com/locate/jvolgeores Evaluating Titan2D mass-flow model using the 1963 Little Tahoma Peak avalanches, Mount Rainier, Washington M.F. Sheridana,*, A.J. Stintona, A. Patrab, E.B. Pitmanc, A. Bauerb, C.C. Nichitac aDepartment of Geology, 876 Natural Science Complex, University at Buffalo, Buffalo NY, 14260, USA bDepartment of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo NY, 14260, USA cDepartment of Mathematics, University at Buffalo, Buffalo NY, 14260, USA Accepted 29 June 2004 Abstract The Titan2D geophysical mass-flow model is evaluated by comparing its simulation results and those obtained from another flow model, FLOW3D, with published data on the 1963 Little Tahoma Peak avalanches on Mount Rainier, Washington. The avalanches, totaling approximately 10Â106 m3 of broken lava blocks and other debris, traveled 6.8 km horizontally and fell 1.8 km vertically (H/L=0.246). Velocities calculated from runup range from 24 to 42 m/s and may have been as high as 130 m/s while the avalanches passed over Emmons Glacier. Titan2D is a code for an incompressible Coulomb continuum; it is a depth-averaged, dshallow-waterT, granular-flow model. The conservation equations for mass and momentum are solved with a Coulomb-type friction term at the basal interface. The governing equations are solved on multiple processors using a parallel, adaptive mesh, Godunov scheme. Adaptive gridding dynamically concentrates computing power in regions of special interest; mesh refinement and coarsening key on the perimeter of the moving avalanche. The model flow initiates as a pile defined as an ellipsoid by a height (z) and an elliptical base defined by radii in the x and y planes.
[Show full text]